Trellis Design (Blackberries)

Not sure if this is right place, but figured I'd post here anyways.

Need to build about 50-60' trellis for Triple Crown Blackberries (this strain is "creeping" or whatever, meaning it will grow along ground if left untouched). I have 10 TC plants and plan to use treated 4x4 (only using treated because I want it to last...hate the chemicals used) and have a 2 wire system with first wire around 24-30" above ground with top wire about 48" or a little more above ground. Wire will be 12.5 ga high-tensile wire and will use ratchet tensioners to keep wire tight.

At each end, I plan on having 2 4x4s about 8' apart for 8' 2x4 to connect the top of posts then wire connecting bottom of very end post to top of next post to brace it. I'm trying to build it as sturdy as possible, but thinking the blackberries won't be all that heavy (like grapes). I will do the 50' span with no posts between. Will this hold? or should I put another post in middle?

Also, I have about 18 semi-erect blackberries (arapaho, apache and kiowa) and plan on doing a "T" style trellis for them. This one will be about 100' long. Plan is to have wires on top 3' apart using 2x4 across the 4x4 post and halfway down, have another smaller "T" to help keep the younger stalks off ground. Wondering how much pressure the plants will have on wires when just "leaning" on them. I'm also thinking it won't be that much weight. I'm planning to put at least 2 posts between the 100' span to hold wires out.

Also, should I use concrete on posts? Will be about 3' deep leaving 5' above ground. Soil is sandy on top then clay below.

Hope this makes sense. Any help/suggestions appreciated. Was supposed to put the posts in ground this weekend, but got sidetracked. Blackberries were bought bare root and placed in pots this winter and are starting to grow really well now that it's finally warm out. Would like to get in ground ASAP.

And one other thing...anyone know where to get a roll of 12.5ga high tensile wire that is less than 4,000 feet long? Most places I have found that did sell smaller rolls do not do so any longer.

Any person is entitled to their own opinion, but not to their own facts and outcomes. So one may believe as they will, but will be held accountable by the numbers for their beliefs. At the end of the day, life is a school of probability. Jesse via Jesse's Cafe Americain

Re: Trellis Design (Blackberries)

Any person is entitled to their own opinion, but not to their own facts and outcomes. So one may believe as they will, but will be held accountable by the numbers for their beliefs. At the end of the day, life is a school of probability. Jesse via Jesse's Cafe Americain

Re: Trellis Design (Blackberries)

Originally Posted by schoolsout

Not sure if this is right place, but figured I'd post here anyways.

Need to build about 50-60' trellis for Triple Crown Blackberries (this strain is "creeping" or whatever, meaning it will grow along ground if left untouched). I have 10 TC plants and plan to use treated 4x4 (only using treated because I want it to last...hate the chemicals used) and have a 2 wire system with first wire around 24-30" above ground with top wire about 48" or a little more above ground. Wire will be 12.5 ga high-tensile wire and will use ratchet tensioners to keep wire tight.

At each end, I plan on having 2 4x4s about 8' apart for 8' 2x4 to connect the top of posts then wire connecting bottom of very end post to top of next post to brace it. I'm trying to build it as sturdy as possible, but thinking the blackberries won't be all that heavy (like grapes). I will do the 50' span with no posts between. Will this hold? or should I put another post in middle?

Also, I have about 18 semi-erect blackberries (arapaho, apache and kiowa) and plan on doing a "T" style trellis for them. This one will be about 100' long. Plan is to have wires on top 3' apart using 2x4 across the 4x4 post and halfway down, have another smaller "T" to help keep the younger stalks off ground. Wondering how much pressure the plants will have on wires when just "leaning" on them. I'm also thinking it won't be that much weight. I'm planning to put at least 2 posts between the 100' span to hold wires out.

Also, should I use concrete on posts? Will be about 3' deep leaving 5' above ground. Soil is sandy on top then clay below.

Hope this makes sense. Any help/suggestions appreciated. Was supposed to put the posts in ground this weekend, but got sidetracked. Blackberries were bought bare root and placed in pots this winter and are starting to grow really well now that it's finally warm out. Would like to get in ground ASAP.

And one other thing...anyone know where to get a roll of 12.5ga high tensile wire that is less than 4,000 feet long? Most places I have found that did sell smaller rolls do not do so any longer.

Go to Lowes and buy the wire like you put on top and bottom of a chain link fence. They come is 100 foot rolls and the wire is about 3/16" in diameter. I would for sure pick up a few sacks of sack-crete while at Lowes getting your treated post, wire and 2x4's and concrete your post. 2x4's aren't the best for tensioning wire, they don't have much lateral strength and bow quite easily. I think I would look a using some 2" schedule 40 galvanized pipe, it will hold tension much better and not rot or bow with age.

Re: Trellis Design (Blackberries)

I'd suggest the following...

1) Find out the weight of the berries and the number each plant can support. This will give you a better idea of the weight the wire will support.
2) 12.5 Gauge wire is fine and can be purchased at Home Depot in 400 foot rolls (or circles - not "really" rolls). I've also bought short sections at Tractor Supply (300+ length) - but they don't always have stock.
3) 50 foot between posts is too far in my opinion - put another post in. I'd also suggest switching from 4x4's to round CCA posts - they are MUCH stonger. You only need a few - so cost shouldn't be an issue. I'm using 5" round 8 foot CCA posts for line posts in our vineyard (which is a bit of overkill). Those are under $10 from my local lumber yard - your price may vary. I'd STRONGLY suggest the end posts on your H Brace be larger. I went with 6" round 10 foot CCA posts for the ends on our vineyard trellis. Only the end posts needed to be set in concrete. I'd also use another of the 5" 8 footers for the cross brace. If you're still stuck on using square posts, then at a minimum skip the idea to use a 2x4 for the cross brace. The cross brace needs to be a 4x4 as well.

One more thing - concrete for posts (40 lb bags) can be purchased at Home Depot for about $4 a bag. It's the RED bag. Works great. Just dump the contents of the bag in the hole and then add 1/2 to 1 gallon of water. Dries HARD in 4 hours and is ready to use the next day.

Re: Trellis Design (Blackberries)

If you don't want the chemicals from the treated lumber then do you have any locust trees? Cut them for the posts, strip the bark and they will last 40-50 years if not longer. There are other trees that would do similar without needing to be treated.

I use mostly treated posts in my vineyards but that is because it is easier for me. I use locust for the end posts though because the locust will outlast the treated 2-1 easily. I don't split the locust trees either, I put them in full size so I am selective in what trees I cut. The biggest posts I can and will use for end posts are 10" diameter but each posts gets smaller as you cut. Downside to locust is it is extremely hard when dry so pounding staples or nails after it is dried can be difficult.

Re: Trellis Design (Blackberries)

Originally Posted by SanDucerro

I'd suggest the following...

1) Find out the weight of the berries and the number each plant can support. This will give you a better idea of the weight the wire will support.
2) 12.5 Gauge wire is fine and can be purchased at Home Depot in 400 foot rolls (or circles - not "really" rolls). I've also bought short sections at Tractor Supply (300+ length) - but they don't always have stock.
3) 50 foot between posts is too far in my opinion - put another post in. I'd also suggest switching from 4x4's to round CCA posts - they are MUCH stonger. You only need a few - so cost shouldn't be an issue. I'm using 5" round 8 foot CCA posts for line posts in our vineyard (which is a bit of overkill). Those are under $10 from my local lumber yard - your price may vary. I'd STRONGLY suggest the end posts on your H Brace be larger. I went with 6" round 10 foot CCA posts for the ends on our vineyard trellis. Only the end posts needed to be set in concrete. I'd also use another of the 5" 8 footers for the cross brace. If you're still stuck on using square posts, then at a minimum skip the idea to use a 2x4 for the cross brace. The cross brace needs to be a 4x4 as well.

One more thing - concrete for posts (40 lb bags) can be purchased at Home Depot for about $4 a bag. It's the RED bag. Works great. Just dump the contents of the bag in the hole and then add 1/2 to 1 gallon of water. Dries HARD in 4 hours and is ready to use the next day.

Why did you set your end posts in concrete? Around here I have seen a lot of different options. I use earth anchors a few feet out from the end post and run a wire from the top of the post to the anchor. On vineyards where there are visitors (pick your own operations) they use anchors but set them one post in and the top wire is stretched between those first posts in and then there is just a short length between the end post and the first post in but it allows them to have a solid anchor without a trip hazard. I've also seen end posts with wood bracing like on a fence as well. But I've never heard of anyone using concrete on any of their posts here so I would enjoy learning what your thoughts were in choosing to do so.

How far along are your vines so far? My concords are just about to break out of dormancy. Been a long winter here but hopefully it means it will be a great growing season.

Re: Trellis Design (Blackberries)

Originally Posted by Robert_in_NY

Why did you set your end posts in concrete?

From a personal perspective I don't like wires and augers, so I went with H Braces. It's nothing more than a "look" I want. Since the rows are fairly long and there will be no additional guide wires I felt the concrete was needed. Having said that, we're in the first stages of establishing our vinyard, so the posts are not even set yet. They have been delivered (and it's a very BIG pile of posts I might add - a little over 400 total), and the schedule says we're installing next week. Originally, the "plan" was to use the space between the braces for an additional vine, but I don't think I'll need the additional space now that I've reconfigured the vineyard layout (popped a fence out another 16 feet).

Originally Posted by Robert_in_NY

How far along are your vines so far? My concords are just about to break out of dormancy. Been a long winter here but hopefully it means it will be a great growing season.

Well, if the nursery ever delivers them... We ordered 700 Black Spanish and 700 Blanc Du Bois from Fairhaven Nursery in NE Texas in September. These are the two vines that grow best in our area. The original delivery date was late February or early March, but the weather in NE Texas has been rather harsh this year. As such, the Black Spanish are not ready for delivery yet (should be ready in about two weeks). The Blanc Du Bois are ready now, but since they are shipping the order on their dime they want to do a single delivey.